Aircraft use inertial measurement units (IMUs) to provide attitude solutions (e.g., pitch, roll and heading) along with inertial solutions (e.g., accelerations and angular body rates, which velocity can be determined therefrom) to various displays and systems of the aircraft. Redundant IMUs are oftentimes installed on board an aircraft as a safety measure in case of equipment failure and to provide confirmation of correct readings. In many conventional implementations, three IMUs are used. If one IMU fails, having only two reliable sources for attitude measurements is not problematic in itself, but a situation can develop where one of the two remaining in-service IMUs degrades during flight and begins to output attitude data that includes some level of bias error. In that case, a flight crew needs to be alerted to the problem and needs to be able to determine which of the IMUs is providing accurate attitude measurements and which is not.
For the reasons stated above and for the reasons stated below which will become apparent to those skilled in the art upon reading and understanding the specification, there is a need in the art for alternate systems and methods for attitude fault detection in an IMU.